1. Field of the Invention
The present invention relates to a light-emitting element, a light-emitting module including the light-emitting element, a light-emitting panel including the light-emitting module, and a light-emitting device including the light-emitting panel. In particular, the present invention relates to a light-emitting element in which a layer containing a light-emitting organic compound is interposed between a pair of electrodes, a light-emitting module including the light-emitting element, a light-emitting panel including the light-emitting module, and a light-emitting device including the light-emitting panel.
2. Description of the Related Art
Mobile phones, personal computers, smartphones, e-book readers, and the like have come into widespread use, and these electronic devices have come into popular use. Moreover, these electronic devices are multifunctional, and thus are used for relatively simple work which has conventionally been done with stationery (specifically, schedule management, address listing, making notes, and the like which have conventionally been done with a datebook). As the frequency of use of these electronic devices in our life increases, a reduction in power consumption of these electronic devices is expected so that these electronic devices can be used continuously for a ling time.
Efforts have been made to reduce power consumption of a variety of electronic devices in terms of energy issues. For example, a light-emitting element with excellent energy conversion efficiency has been studied in order to reduce power consumption of lighting devices.
A light-emitting element in which a layer containing a light-emitting organic compound (also referred to as EL layer) which has a film shape is provided between a pair of electrodes is known. Such a light-emitting element is referred to as, for example, an organic EL element, and light emission can be obtained from the light-emitting organic compound when voltage is applied between the pair of electrodes. Light-emitting devices such as a lighting device and a display device including an organic EL element are known. Patent Document 1 discloses an example of a display device including an organic EL element.
Further, a structure in which light is extracted from a side opposite to an element substrate side (i.e., top emission structure) has been proposed. Patent Document 2 discloses the invention in which one of electrodes is formed using a stacked layer of a film of an alloy containing aluminum and a film containing a metal or a metal oxide.